Round tenons have been long and widely used in woodworking, particularly in furniture making, and most particularly in chair making. Such tenons are used for attachment of chair rungs to chair legs and for securing other furniture and chair parts. Round tenons may be provided by securing a short length of round dowel in a suitably shaped and placed hole on the part requiring a tenon. More typically however, a round tenon is formed on the part itself, which part may also be round or have a square, rectangular or differently shaped cross section.
Many tenons, particularly in chair parts, have a truncated conical shape, i.e. are round but tapered. Such tenons are desirable in that they provide a snug fit in an appropriately shaped mortise (that is tapered). However, slight relative movement between the joint members loosens the joint. By contrast, accurately sized cylindrical tenons can move longitudinally in a mortise without loosening. Furthermore, the mortise-containing furniture member can lock around a cylindrical the tenon as the mortise member dries and shrinks.
A substantial number of methods and devices have been used for forming such tenons. They may be formed by hand using a pocket knife, draw knife, chisel, spoke shave or other tools. They may be formed on general purpose equipment like lathes and drill presses, and in some instances they may be formed using dedicated machines like the Stanley number 77 dowel making machine (although this machine will accept only a limited range of sizes of workpieces). There are also a variety of tenon forming cutters intended to be rotated against a workpiece utilizing a brace. Finally, high speed tenon-forming cutters for use in a drill press are available.
Some such devices are intended to form tenons having only a particular diameter or group of predetermined diameters. Others are purportedly capable of producing a range of tenon diameters. Most of these devices, including for the Stanley number 77 dowel making machine, have a cutting blade or blades that are difficult to sharpen because, among other reasons, their shape is complex. Still other devices are useful principally only in a drill press and form small diameter plugs, tenons or dowels, but are unwieldy, if not impossible to use in forming a tenon on the end of a relatively long, small diameter workpiece. None of these prior devices have been capable of forming relatively long tenons of small diameters (e. g., 1/4", 3/8", 1/2 and 9/16") on the end of a rung or other slender workpiece with an attractive, relatively wide shoulder, particularly a shoulder sloping away from the tenon.
The continuing need for cylindrical tenons described above, and this resurgence in the popularity of rustic furniture, have created the need for an economical but improved tenon-forming tool. Tenons of these small sizes arc useful, for instance, on chair rungs and decorative details such as lattice, trellis and fan-light frames.
It is thus an object of this invention to provide a tenon cutter for forming attractive, accurately sized cylindrical tenons with attractive tenon shoulders on components of rustic and other furniture.
It is a further object of the present invention to provide a tenon cutter that uses a blade that may be easily and quickly sharpened without significant risk of altering the desired blade profile and with minimal sharpening skill.
Yet another object of the present invention is the provision of a tenon cutter design that can be manufactured with sufficient economy to enable retail sale of the tenon cutter, or of a set of tenon cutters in different diameters, at an attractively low price.